The present invention relates generally to an oven and more particularly to a low moisture/closed door broil oven ventilation system.
Known oven designs include single ovens, double ovens and combination ovens that have a conventional oven and a microwave oven. Of course, the ovens may be used for roasting certain items including turkeys, chickens or other high moisture foods. The hot, moist air generated during the roasting of such foods must be dissipated by some sort of ventilation system. Ventilation systems are provided in most ovens for venting some hot air from the oven and to remove moisture when cooking such a high moisture load. However, it is unacceptable to have a large amount of the moisture vented out of the oven because of condensation that could occur on the front of the oven or on the cabinetry surrounding the oven.
In addition, most ovens have a broiler. The broilers are typically used for cooking such items as steaks and other meats at high temperatures. However, when cooking a steak or the like in the broiler, a large amount of smoke can develop because of the fat in the steak and the high temperatures at which the meat is being cooked. It is obviously undesirable for the ventilation or exhaust system of the oven to pump smoke out of the oven and into the kitchen. Thus, a ventilation system for an oven needs to meet certain design and performance requirements such as those that follow.
There are two key items involved in the evacuation of air from an oven. The first is the volumetric exit velocity of the air from the oven cavity. If the air is evacuated too quickly from the oven cavity, this can negatively affect the cooking performance and the oven preheat time. If the evacuation of the air is too slow, then after the completion of a closed door broil, when the user opens the door of the oven, a large unacceptable smoke cloud could pour forth from the oven and enter the kitchen. Thus, a ventilation system must be designed to handle the dissipation of the smoke cloud to prevent the kitchen from being polluted with smoky air.
The second key item in the design of an oven ventilation system is the exhaust air temperature. If the temperature of the exhaust air is too hot then there is a potential of burning the user or damaging kitchen cabinets that surround the oven. Also, an exhaust temperature that is too high may have a negative impact on the efficiency of the oven. For example, this condition would draw off too much heat that should be used for cooking. Also, if the exhaust air temperature is too low, then there is a condensation of the cooking by-products and steam as the exhaust exits the oven. This situation can cause damage to surrounding cabinets and possibly violate certain Underwriter's Laboratory or other safety requirements.
Several attempts have been made to combat the problems of oven ventilation systems and provide better ventilation for an oven. For example, U.S. Pat. No. 4,601,279 discloses an oven with a venting system for cooling oven controls. In FIG. 4, a vertical opening 31 exhausts air from the oven cavity into a passage exhausting cooling air. In addition, a catalytic cartridge 32 is provided. The vent system discharges through vents across the entire front of the oven after cooling air has mixed with hot air from the oven. Thus, this configuration provides a low moisture, low speed air exhaust from the oven.
Also, U.S. Pat. No. 4,654,508 discloses an electronic oven having an oven vent and catalyst reactor 11 exhausting into a cooling duct 10 so that air is mixed prior to exiting the oven cabinet. Also, a deflector and a baffle 18 are arranged in the air flow to help pull and mix air from the oven cavity.
Further, U.S. Pat. No. 4,331,124 discloses a built-in oven having an oven vent tube 48 exhausting air into a cooling air chamber 54 to be mixed therein prior to exhausting from the oven cabinet.
Thus, a need has arisen for a ventilation system that is cost effective, easily manufactured and provides the proper balance of exhaust temperature with the proper exit air velocity to achieve low moisture exhaust and optimum closed door broiling performance from an oven.